Coronary Artery Calcium Versus Pooled Cohort Equations Score for Primary Prevention Guidance: Randomized Feasibility Trial.

Objectives: This study sought to determine the feasibility of performing an extensive randomized outcomes trial comparing a coronary artery calcium (CAC)- versus a pooled cohort equations (PCE) risk score-based strategy for initiating statin therapy for primary atherosclerotic cardiovascular disease (ASCVD) prevention.

Background: Statin therapy is standard for the primary prevention of ASCVD in subjects at increased risk. National guidelines recommend using the American College of Cardiology/American Heart Association PCE risk score to guide a statin recommendation. Whether guidance by a CAC score is equivalent or superior is unknown.

Methods: CorCal (Effectiveness of a Proactive Cardiovascular Primary Prevention Strategy, With or Without the Use of Coronary Calcium Screening, in Preventing Future Major Adverse Cardiac Events) was a randomized trial consenting 601 patients without known ASCVD, diabetes, or prior statin therapy recruited from primary care clinics and randomized to CAC- (n = 302) or PCE guidance (n = 299) of statin initiation for primary prevention. Enrolled subjects and their physicians made final treatment decisions. Primary outcomes compared the proportion of statin recommendations received and subject adherence over 1 year between CAC- and PCE-arm subjects. Modeled medical costs, adverse effects, and low-density lipoprotein-cholesterol (LDL-C) were additional measures of interest.

Results: Subjects were well matched, and 540 (89.9%) completed entry testing and received a protocol-based recommendation. A statin was recommended in 101 (35.9%) CAC-arm and 124 (47.9%) PCE-arm subjects (P = 0.005). Compared to PCE-based recommendations, CAC-arm subjects were reclassified from statin to no statin in 36.0% and from no statin to statin in 5.6% of cases, resulting in a total reclassification of 20.6%. Physicians accepted the study-dictated recommendation to start a statin in 88.1% of CAC-arm vs 75.0% of PCE-arm subjects (P = 0.01). Patient-reported adherence to this recommendation at 3 months was 62.2% vs 42.2%, respectively (P = 0.009). At 1 year, statin adherence remained superior, LDL-C levels were lower, estimated costs were similar or reduced in CAC subjects, and few events occurred.

Conclusions: CAC guidance may be a more efficient, personalized, cost-effective, and motivating approach to statin initiation and maintenance in primary prevention. This feasibility phase of CorCal should be regarded as hypothesis-generating with respect to cardiovascular outcomes, which is being addressed in a large, longer-term outcomes trial. (Effectiveness of a Proactive Cardiovascular Primary Prevention Strategy, With or Without the Use of Coronary Calcium Screening, in Preventing Future Major Adverse Cardiac Events [CorCal]; NCT03439267).